Re: latest -git: BUG at fs/jfs/namei.c:512 assert(ip->i_nlink)

From: Dave Kleikamp
Date: Fri Jul 18 2008 - 13:16:30 EST


On Fri, 2008-07-18 at 10:10 +0200, Vegard Nossum wrote:

> But whether it truly helped or not, I don't know. I got something different now:
>
> jfs_unlink: dtDelete returned -116
> jfs_unlink: dtDelete returned -116
> ------------[ cut here ]------------
> kernel BUG at fs/inode.c:262!

BUG_ON(inode->i_data.nrpages);

> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Pid: 387, comm: jfsCommit Not tainted (2.6.26-03415-gdf3030b #45)
> EIP: 0060:[<c01b96f9>] EFLAGS: 00010206 CPU: 0
> EIP is at clear_inode+0x149/0x160
> EAX: 00000005 EBX: f56e283c ECX: f7242fd0 EDX: 00000000
> ESI: f56e2568 EDI: 00000000 EBP: f79f9f0c ESP: f79f9f04
> DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
> Process jfsCommit (pid: 387, ti=f79f8000 task=f7242fd0 task.ti=f79f8000)
> Stack: 00000001 f56e283c f79f9f24 c02de258 c08f7ba0 f79f9f24 c02de220 f56e283c
> f79f9f34 c01b9ba1 f56e283c 00000000 f79f9f44 c01b9d67 f56e283c 00000000
> f79f9f50 c01b8be7 f56e283c f79f9f9c c02fd5b5 f88261bc f79f9f70 c0159173

>
> ...but it might just be a different error altogether.

I think it is. Your test corrupt more than just di_nlink, right? There
is a test in jfs_delete_inode() for JFS_IP(inode)->fileset ==
FILESYSTEM_I. If the test fails, we don't call truncate_inode_pages().
Nowhere do we validate that fileset = FILESYSTEM_I when we read the
inode from disk.

I'm pondering whether it would be okay to remove the silly test in
jfs_delete_inode(), or whether I need to validate the field when we read
in the inode.

Hmm. The fileset is written to the journal, so it really should be
validated.

Here's another patch

JFS: validate di_fileset when reading inode from disk.

Signed-off-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx>

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index d6363d8..19df0dd 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -391,7 +391,10 @@ int diRead(struct inode *ip)
dp += rel_inode;

if (ip->i_ino != le32_to_cpu(dp->di_number)) {
- jfs_error(ip->i_sb, "diRead: i_ino != di_number");
+ jfs_error(ip->i_sb, "JFS diRead: i_ino != di_number");
+ rc = -EIO;
+ } else if (dp->di_fileset != cpu_to_le32(FILESYSTEM_I)) {
+ jfs_error(ip->i_sb, "JFS diRead: inode is corrupt");
rc = -EIO;
} else if (le32_to_cpu(dp->di_nlink) == 0)
rc = -ESTALE;

--
David Kleikamp
IBM Linux Technology Center

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